US6826265B1 - DSL-ready pots device and method - Google Patents
DSL-ready pots device and method Download PDFInfo
- Publication number
- US6826265B1 US6826265B1 US09/579,314 US57931400A US6826265B1 US 6826265 B1 US6826265 B1 US 6826265B1 US 57931400 A US57931400 A US 57931400A US 6826265 B1 US6826265 B1 US 6826265B1
- Authority
- US
- United States
- Prior art keywords
- pots
- subscriber loop
- hook switch
- low
- pass filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/738—Interface circuits for coupling substations to external telephone lines
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
- H04Q2213/13039—Asymmetrical two-way transmission, e.g. ADSL, HDSL
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q2213/00—Indexing scheme relating to selecting arrangements in general and for multiplex systems
- H04Q2213/1319—Amplifier, attenuation circuit, echo suppressor
Definitions
- the present invention generally relates to the art of data communications and telephony. More particularly, the invention relates to a plain old telephone system (POTS) device, or a device that operates in connection with the Public Service Telephone Network (PSTN), for example but not limited to, a telephone, facsimile machine, analog modem, caller ID system, speaker phone, cordless phone, etc., that employs an on-board POTS filter to enable reliable and efficient decoupling of a POTS channel from one or more xDSL channels on a telephone connection, while reducing interference imposed upon the xDSL channels.
- POTS plain old telephone system
- PSTN Public Service Telephone Network
- a high speed digital subscriber line e.g., asymmetric DSL (ADSL), symmetric DSL (SDSL), rate adaptive digital subscriber line (RADSL), very high speed ADSL (VADSL), etc.
- XDSL high speed digital subscriber line
- SDSL symmetric DSL
- RADSL rate adaptive digital subscriber line
- VADSL very high speed ADSL
- POTS plain old telephone system
- the signals are typically separated in frequency.
- the POTS channel usually exhibits a frequency spectrum of about 0 KHz to about 4 KHz, whereas the XDSL channels exhibit a frequency spectrum of about 20 KHz to about 500 KHz.
- a POTS splitter also known as a POTS filter, a telephone filter, a microfilter, or a CP (customer premises) filter, has traditionally been utilized to decouple the channels, or separate the POTS channel from the other channels, due to non-linearities inherent in most, if not all central office powered telephones.
- the POTS filter is usually implemented in series with the telephone in order to reduce the DSL power imparted on the telephone electronics, which imposes interference upon the POTS and the DSL signals.
- a POTS splitter is typically a passive or active one-to-two port device.
- the POTS splitter is installed between a telephone jack and the telephone itself and is also connected to a DSL device. It includes a POTS filter (a one-to-one port device) situated between the telephone line and the telephone that is designed to minimize high frequency transients produced by on-hook/off-hook transitions, so as to prevent tainting or slowing of the high speed data on the DSL channel. Also, it is usually configured to provide a high impedance to the telephone line in the DSL frequency band in order to prevent DSL power from being imparted on the POTS communications device that is connected to the line. In essence, the filter reduces incident DSL signal power to reduce DSL signal intermodulation (IMD), which undesirably creates audio noise heard in the receiver of a telephone, and interferes with the DSL signal.
- IMD DSL signal intermodulation
- POTS splitters are usually expensive devices and are oftentimes installed on a physical wall of a customer premises (CP), such as on an outside wall of a building.
- CP customer premises
- POTS splitters require installation by a skilled telephone company worker, not the premise owner, resulting in undesirable installation time, labor, and expense.
- Distributed microfilters per phone are an increasingly used alternative to the outside wall splitter for the reason cited.
- POTS splitters and filters have been the subject of several industry standards bodies. For example, see American National Standards Institute, ANSI T1.413-1995, Sections 8 and 10, regarding ADSL/POTS splitters. Moreover, as an example of a possible implementation of a POTS splitter, see J. Cook, P. Sheppard, “ADSL and VADSL Splitter Design and Telephony Performance,” IEEE Journal on Selected Areas in Communications , December 1995.
- a passive one-to-one port POTS filter for enabling decoupling of a first channel, such as a POTS channel, from a second channel, such as an xDSL channel, that is communicated simultaneously with the first channel on a telephone connection, while permitting and not appreciably interfering with the second channel.
- the POTS filter can be connected between the telephone jack and a telephone or can be situated within the telephone.
- Each POTS filter has a passive automatic control mechanism and a passive first channel filter (e.g., a POTS filter).
- the automatic control mechanism is configured to isolate the first channel filter when a respective first communications device is inactive (on-hook). Further, the distributed filter is configured to interface communications on the first channel (e.g., POTS channel) on the telephone connection with the respective first communications device when the first communications device is active (off-hook). Moreover, a second communications device (for example, a modem) is connected to the telephone connection and communicates signals over a second channel (xDSL, e.g., ADSL, SDSL, RADSL, VADSL, etc.), simultaneously with the first channel.
- xDSL e.g., ADSL, SDSL, RADSL, VADSL, etc.
- the passive distributed filter system implements a control mechanism, and it would be desirable to implement such a filtering function with less complexity and requisite circuitry.
- the filter usually contains inductors in series with the telephone line and capacitors in parallel with the telephone. The presence of these reactive elements introduces concerns about excessive POTS attenuation, reduced PSTN network stability, poor telephone sidetone, increased ringer loading, and degraded termination impedance, especially with multiple telephones on the telephone line (a typical scenario).
- a heretofore unaddressed need exists in the industry for an improved filtering systems and methods.
- the present invention provides a plain old telephone system (POTS) device, for example but not limited to, a telephone, facsimile machine, analog modem, caller identification (ID) system, speaker phone, cordless phone, etc., that employs an on-board POTS filter to enable reliable and efficient decoupling of a POTS channel from one or more XDSL channels on a telephone connection, while permitting and not interfering with the XDSL channels.
- POTS filter is situated after the telephone connection switch (for example, a hook switch).
- the switch effectively isolates the POTS filter from the telephone line when the POTS device is disconnected, or is “on hook,” and interfaces the telephone line through the POTS filter to the POTS transmitter, receiver, or transceiver when the POTS device is connected, or is “off hook.”
- the POTS device which connects to a subscriber loop associated with the public service telephone network (PSTN), includes a subscriber loop connection switch (for example, a hook switch), POTS electronics (including a transmitter, receiver or both (transceiver)), and a low pass filter (LPF) interconnecting the subscriber loop connection switch with the POTS electronics.
- the switch effectively isolates the POTS filter from the telephone line when the POTS device is disconnected, or is on hook, and interfaces the telephone line through the POTS filter to the POTS electronics when the POTS device is connected, or is off hook.
- the arrangement enhances DSL device performance, network stability, sidetone, ringer load, and termination impedance and allows greater flexibility in the choice of filter elements, in that passive and active elements can be utilized and in that filters of higher order can be employed.
- the invention can also be conceptualized as providing a method for a POTS device that is connected to a subscriber loop.
- the method can be summarized by the following steps: coupling a subscriber loop connection switch to a POTS transmitter, receiver, or transceiver; and filtering out high frequency signals from voice band signals communicated between the loop connection switch and the transmitter, receiver, or transceiver.
- the invention has numerous advantages, a few of which are delineated hereafter, as merely examples.
- An advantage of the invention is that it provides a way of achieving telephone XDSL compatibility without an external CP telephone filter. That is, the invention teaches a method for telephone manufacturers to design and produce DSL compatible telephones.
- Another advantage of the invention is that it can be used in any data communication device that connects to a single physical connection having at least two communications channels (e.g., a high speed xDSL link in combination with a POTS link), where the channels are separated by frequency, and that includes a telephone line connection/disconnection switch (such as a hook switch).
- a single physical connection having at least two communications channels (e.g., a high speed xDSL link in combination with a POTS link), where the channels are separated by frequency, and that includes a telephone line connection/disconnection switch (such as a hook switch).
- Another advantage of the invention is that it can be used to effect economical deployment of a XDSL communications channels simultaneously in combination with a POTS communications channel on a telephone connection.
- Another advantage of the invention is that it is simple in design, efficient in operation, and easily and economically implemented and manufactured on a mass scale.
- Another advantage of the invention is that passive components, active components, or a combination of both can be utilized in the filter.
- Another advantage of the invention is that it is very desirable for typical homeowners and consumers in that it does not require sophisticated installation.
- Another advantage of the invention is that it meets surge and safety requirements of industry standard UL1950, Third Edition, and applicable requirements of FCC, Part 68.
- FIG. 1 is a circuit diagram of a POTS device employing an on-board POTS filter in accordance with the present invention
- FIG. 2 is a physical view of a distributed POTS filter (DPF) system utilizing a plurality of POTS devices of FIG. 1 at a customer premises (CP);
- DPF distributed POTS filter
- FIG. 3 is a functional view of the DPF system of FIG. 2;
- FIG. 4A is a circuit diagram of a possible implementation of a POTS filter of FIG. 1;
- FIG. 4B is a circuit diagram of another possible implementation of a POTS filter of FIG. 1;
- FIG. 4C is a circuit diagram of yet another possible implementation of a POTS filter of FIG. 1, which provides improved sidetone.
- a DSL-ready POTS device in accordance with the present invention is illustrated in FIG. 1 and is generally denoted by reference numeral 10 .
- the DSL-ready POTS device 10 can be, for example but not limited to, a telephone, facsimile machine, analog modem, caller identification (ID) system, speaker phone, cordless phone, etc.
- the DSL-ready POTS device 10 can be directly connected to a subscriber loop 12 having a POTS channel and one or more other coexisting channels, such as high speed digital subscriber line channels (XDSL, e.g., T1, ADSL, SDSL, RADSL, VADSL, etc.) to effectively decouple the POTS channel from the loop 12 , while minimizing adverse effects to the one or more DSL channels.
- XDSL high speed digital subscriber line channels
- the DSL-ready POTS device 10 includes a telephone line connection switch 13 , for instance a hook switch in the case of a conventional telephone, that connects the subscriber loop 12 to a one-to-one port POTS filter 17 , when appropriate, as well as disconnects the subscriber loop 12 and the POTS filter 17 , when appropriate.
- the POTS filter 17 preferably exhibits the following approximate signal characteristics: ⁇ 3 dB cutoff frequency of 4 KHz to 25 KHz; a stop band of approximately 25 KHz to 1.104 MHz; stop-band attenuation of at least 20 dB; and a passband of 0 (DC) to ⁇ 3 dB cutoff frequency.
- Some POTS devices 10 will have a ringer 15 , such as in the case of a conventional telephone, and as illustrated by phantom lines in FIG. 1, the ringer 15 , if present, would connect directly (unswitched) to the subscriber loop 12 .
- a transmitter, receiver, or both i.e., a transceiver
- the transmitter, receiver, or transceiver 18 implements the modulation and other signal processing functions, as appropriate.
- the filter 17 could be situated somewhere within the electronics block 18 .
- the key is placing it after a switch that connects and disconnects it relative to the subscriber loop 12 .
- Some circuit elements can be interposed between the switch 13 and the POTS filter 17 , for example but not limited to, a polarity guard, which is well known in the art and which enables the tip and ring lines to be interchanged without hazard or disfunction.
- the telephone line connection switch 13 automatically either isolates or interfaces the POTS filter 17 (in the telephony voice spectrum), based upon the connection status (e.g., off-hook or on-hook, respectively) of the POTS device 10 .
- connection status e.g., off-hook or on-hook, respectively
- the POTS filter 17 is situated beyond the switch 13 within the DSL-ready POTS device 10 .
- the POTS filter 17 is physically separate from the telephone line when the POTS device 10 is in a disconnected status and does not degrade the DSL device performance. In fact, the arrangement improves network stability, sidetone, ringer load, and termination impedance.
- the POTS filter 17 is not subjected to ringing voltage (except perhaps during ring trip).
- the POTS filter 17 of FIG. 1 is a one-to-one port device, unlike conventional POTS splitters, which are typically one-to-two port devices with one port receiving the combined signal and the other two each outputting a respective channel.
- the functionality of the POTS filter 17 and the POTS splitter are similar in that they both parse out a POTS channel from a communications connection having more than one communications channel.
- the POTS filter 17 of FIG. 1 can be implemented with a POTS splitter, if desired, by using only two of its ports. Many designs of POTS splitters are known in the art.
- a distributed POTS filter (DPF) system 28 that utilizes a plurality of DSL-ready POTS devices 10 (FIG. 1) is shown in FIG. 2 .
- a customer premises (CP) 31 is shown with a plurality of the DSL-ready POTS device 10 connected directly to CP wiring 16 .
- Any number of DSL-ready POTS devices 10 can be supported, up to the ringer equivalence number (REN) limit.
- the CP wiring 16 can be connected to the subscriber loop 12 by way of a conventional network interface (NI) 37 .
- the network interface 37 is well known in the art.
- One or more data terminal equipment (DTE) devices 39 can be interfaced with the CP wiring 16 by way of any suitable communications device 41 , for instance, a data channel modem, or digital modem, in order to permit communications over one or more of the XDSL channels on the loop 12 .
- a data channel modem or digital modem
- These xDSL channels can exist concurrently with the POTS communications channel on the telephone connection 12 without any appreciable interference to each, in accordance with the invention.
- a local connection 43 interconnects each DTE 39 with a communications device 41 .
- the communications device 41 is a conventional digital subscriber line (DSL) modem.
- DSL digital subscriber line
- a router could also be employed as the communications device 41 .
- FIG. 3 is an abstract functional view of the DPF system 28 (FIG. 2) showing that the DPF system 28 can be viewed as implementing a plurality of parallel distributed POTS filters 17 , each of which is situated within a respective DSL-ready POTS device 10 . As shown, these distributed POTS filters 17 are in parallel with the DSL channel communications device, the DTE 39 , relative to the CP wiring 16 .
- the POTS filter 17 of FIG. 1 can be configured in many ways and many implementations are known in the art.
- a possible implementation (a nonlimiting example) of the POTS filter 17 is shown in FIG. 4 A and generally denoted by reference numeral 17 ′.
- the POTS filter 17 ′ is essentially a 2nd-order low pass filter (LPF) and is well known in the art.
- the POTS filter 17 ′′ includes, on the tip side, an inductor L 1 connecting the tip line 21 a from the switch 13 (FIG. 1) to the tip line 23 a , which is connected to the transmitter and/or receiver block 18 .
- an inductor L 2 connects ring line 21 b from the switch 13 to the ring line 23 b .
- a capacitor C 1 is connected between lines 23 a , 23 b .
- the circuit exhibits high impedance to high frequency signals (DSL signals) and low impedance to low frequency signals (POTS signals).
- DSL signals high frequency signals
- POTS signals low impedance to low frequency signals
- inductor L 1 , inductor L 2 , and capacitor C 1 have the following circuit values: 8mH, 8mH, and 56 nF, respectively.
- FIG. 4 B Another possible implementation of the POTS filter 17 is shown in FIG. 4 B and generally denoted by reference numeral 17 ′′.
- the POTS filter 17 ′′ is essentially a 4th-order LPF and is well known in the art.
- the POTS filter 17 ′′ includes, on the tip side, an inductor L 1 in series with an inductor L 3 connecting the tip line 21 a from the switch 13 (FIG. 1) to the tip line 23 a , which is connected to the transmitter and/or receiver block 18 (FIG. 1 ).
- an inductor L 2 in series with an inductor L 4 connects ring line 21 b from the switch 13 to the ring line 23 b .
- a capacitor C 1 is connected between nodes 51 a , 51 b .
- a capacitor C 2 is connected between the nodes 23 a , 23 b .
- the circuit exhibits high impedance to high frequency signals (DSL) and low impedance to low frequency signals (POTS signal).
- inductors L 1 -L 4 and capacitors C 1 -C 2 have the following circuit values: 8mH, 8mH, 8mH, 8mH, 56 nF, and 56 nF, respectively.
- FIG. 4 C Still another possible implementation of the POTS filter 17 is shown in FIG. 4 C and generally denoted by reference numeral 17 ′′.
- the POTS filter 17 ′′ of FIG. 4C is basically another LPF and is preferred in that it has demonstrated excellent sidetone performance. Many conventional POTS filters demonstrate very poor sidetone performance.
- the improved POTS filter 17 ′′ of FIG. 4C utilizes a tuning technique (tuning circuits C 3 , R 3 and C 4 , R 4 ) to improve sidetone, but is still a passive POTS filter device.
- the tuned frequency and quality factor Q are optimized to improve sidetone in the region most required, in this case, are optimized in the range between about 1 KHz and about 3 KHz. Note that commonly assigned U.S. Pat. No. 5,848,150 to T. J. Bingel, which is incorporated by reference, describes the POTS filter 17 ′′ in further detail.
- the POTS filter 17 ′′ is implemented by modifying a balanced 5th-order 0.01 dB-ripple Chebyshev filter (note that the 5 th reactance component is based upon a 27 to 33 nF capacitance associated with the second channel communications device and which appears between connections 21 a , 21 b ) with tuning circuit components, comprised of a capacitor (C 3 , C 4 ) in series with a de-Q resistor (R 3 , R 4 , respectively) on each balanced side.
- a balanced 5th-order 0.01 dB-ripple Chebyshev filter note that the 5 th reactance component is based upon a 27 to 33 nF capacitance associated with the second channel communications device and which appears between connections 21 a , 21 b
- tuning circuit components comprised of a capacitor (C 3 , C 4 ) in series with a de-Q resistor (R 3 , R 4 , respectively) on each balanced side.
- the POTS filter 17 ′′ includes, on the tip side, an inductor L 1 connected to the tip line 21 a from the automatic control mechanism 14 (FIG. 1 ).
- a series combination of a capacitor C 3 and a resistor R 3 is connected between the node 51 a and a node 23 a .
- inductor L 1 , inductor L 3 , resistor R 3 , and capacitor C 3 have the following circuit values: 8mH, 8mH, 100 ⁇ , and 1 ⁇ F, respectively.
- an inductor L 2 is connected to the ring line 21 b .
- An inductor L 4 is situated between the nodes 5 b and 23 b . Also, between these nodes 51 b and 23 b is situated a series combination of a capacitor C 4 and a resistor R 4 .
- inductor L 2 , inductor L 4 , resistor R 4 , and capacitor C 4 have the following circuit values: 8mH, 8mH, 100 ⁇ , and 1 ⁇ F, respectively.
- the inductors L 1 and L 2 may be implemented as mutually coupled inductors.
- the inductors L 1 and L 2 may be implemented with a first transformer, and/or the inductors L 3 and L 4 may be implemented with a second transformer. Use of these transformers may reduce the cost of the POTS filter 17 ′′.
- capacitors are connected between the tip and ring sides.
- a capacitor C 2 is connected between tip and ring lines 23 a , 23 b .
- capacitor C 2 is 27 nF.
- a capacitor C 1 is connected between the tip and ring lines 51 a , 51 b .
- the capacitor C 1 is 56 nF.
- the inductors L 1 , L 2 provide high impedance to high frequencies, particularly those frequencies in the xDSL band.
- the capacitors C 3 , C 4 resonate with the inductors L 3 , L 4 in order to parallel resonate at the geometric mean of about 1 KHz and about 3 KHz. This feature improves telephone sidetone performance in the 1 to 3 KHz band by improving impedance (restoring the resistance and capacitive reactance) presented to the telephone 33 as compared to a pure L-C (inductor/capacitor) filter structure in prior art embodiments.
- the filter 17 could be an active filter if it can receive electrical power locally, at least in part.
- the filter 17 could receive electrical power, directly or indirectly, from the outlet, and utilize the power to implement and enhance filtering functionality, as is known in the art.
- the filter 17 (FIG. 1) may be implemented as an unbalanced circuit (for example, in the filter 17 ′, either L 1 or L 2 would be eliminated). All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.
Abstract
Description
Claims (35)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/579,314 US6826265B1 (en) | 2000-02-16 | 2000-05-25 | DSL-ready pots device and method |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US18280500P | 2000-02-16 | 2000-02-16 | |
US09/579,314 US6826265B1 (en) | 2000-02-16 | 2000-05-25 | DSL-ready pots device and method |
Publications (1)
Publication Number | Publication Date |
---|---|
US6826265B1 true US6826265B1 (en) | 2004-11-30 |
Family
ID=33455936
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/579,314 Expired - Lifetime US6826265B1 (en) | 2000-02-16 | 2000-05-25 | DSL-ready pots device and method |
Country Status (1)
Country | Link |
---|---|
US (1) | US6826265B1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020064183A1 (en) * | 2000-10-30 | 2002-05-30 | Peter Larsen | Arrangement and method relating to data-, and telecommunication |
US20030042991A1 (en) * | 2001-03-12 | 2003-03-06 | Glen Cotant | Advanced electronic signal conditioning assembly and method |
US20070280201A1 (en) * | 2006-05-31 | 2007-12-06 | Berkman William H | System and Method for Communicating in a Multi-Unit Structure |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5757803A (en) | 1995-11-27 | 1998-05-26 | Analog Devices, Inc. | Pots splitter assembly with improved transhybrid loss for digital subscriber loop transmission |
US5848150A (en) | 1997-02-26 | 1998-12-08 | Paradyne Corporation | Passive distributed filter system and method |
US6028919A (en) | 1997-12-10 | 2000-02-22 | Paradyne Corporation | Passive distributed filter system and method including caller ID |
US6101216A (en) * | 1997-10-03 | 2000-08-08 | Rockwell International Corporation | Splitterless digital subscriber line communication system |
US6115466A (en) | 1998-03-12 | 2000-09-05 | Westell Technologies, Inc. | Subscriber line system having a dual-mode filter for voice communications over a telephone line |
US6144733A (en) | 1998-01-28 | 2000-11-07 | Globespan Semiconductor, Inc. | Ring filter for pots communication system |
US6301337B1 (en) * | 1997-09-18 | 2001-10-09 | Globespan, Inc. | Combined handset and POTS filter |
US6459790B1 (en) * | 1999-08-27 | 2002-10-01 | Efficient Networks, Inc. | System and method for selective filter isolation |
US6477249B1 (en) | 1997-12-09 | 2002-11-05 | Nortel Networks Limited | Communications signal splitter and filter |
US6483914B1 (en) | 1999-05-06 | 2002-11-19 | Nortel Networks Limited | Telephone filter arrangement |
-
2000
- 2000-05-25 US US09/579,314 patent/US6826265B1/en not_active Expired - Lifetime
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5757803A (en) | 1995-11-27 | 1998-05-26 | Analog Devices, Inc. | Pots splitter assembly with improved transhybrid loss for digital subscriber loop transmission |
US5848150A (en) | 1997-02-26 | 1998-12-08 | Paradyne Corporation | Passive distributed filter system and method |
US6301337B1 (en) * | 1997-09-18 | 2001-10-09 | Globespan, Inc. | Combined handset and POTS filter |
US6101216A (en) * | 1997-10-03 | 2000-08-08 | Rockwell International Corporation | Splitterless digital subscriber line communication system |
US6477249B1 (en) | 1997-12-09 | 2002-11-05 | Nortel Networks Limited | Communications signal splitter and filter |
US6028919A (en) | 1997-12-10 | 2000-02-22 | Paradyne Corporation | Passive distributed filter system and method including caller ID |
US6144733A (en) | 1998-01-28 | 2000-11-07 | Globespan Semiconductor, Inc. | Ring filter for pots communication system |
US6115466A (en) | 1998-03-12 | 2000-09-05 | Westell Technologies, Inc. | Subscriber line system having a dual-mode filter for voice communications over a telephone line |
US6483914B1 (en) | 1999-05-06 | 2002-11-19 | Nortel Networks Limited | Telephone filter arrangement |
US6459790B1 (en) * | 1999-08-27 | 2002-10-01 | Efficient Networks, Inc. | System and method for selective filter isolation |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020064183A1 (en) * | 2000-10-30 | 2002-05-30 | Peter Larsen | Arrangement and method relating to data-, and telecommunication |
US20030042991A1 (en) * | 2001-03-12 | 2003-03-06 | Glen Cotant | Advanced electronic signal conditioning assembly and method |
US7110931B2 (en) * | 2001-03-12 | 2006-09-19 | Pulse Engineering, Inc. | Advanced electronic signal conditioning assembly and method |
US20070280201A1 (en) * | 2006-05-31 | 2007-12-06 | Berkman William H | System and Method for Communicating in a Multi-Unit Structure |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5848150A (en) | Passive distributed filter system and method | |
US6285754B1 (en) | Odd-order low-pass pots device microfilter | |
US6137880A (en) | Passive splitter filter for digital subscriber line voice communication for complex impedance terminations | |
US6963559B2 (en) | Arrangement of local area network | |
US6674843B1 (en) | Apparatus system and method for enabling multi-frequency communication over a telephone network having a billing/tax tone | |
US6144734A (en) | Low-pass filters for splitterless pots and data transmission | |
US7039180B1 (en) | Method and apparatus for enabling multiple protocol communication over a network | |
US6028919A (en) | Passive distributed filter system and method including caller ID | |
US8005206B1 (en) | VDSL splitter | |
US6567519B1 (en) | System and method for processing an input signal communicated on a telephone line | |
US6404347B1 (en) | Alarm filter circuit | |
US6826265B1 (en) | DSL-ready pots device and method | |
US20130259213A1 (en) | Apparatus, method and system for providing new communication services over existing wiring | |
US6459790B1 (en) | System and method for selective filter isolation | |
US6757380B2 (en) | Impedance blocking filter circuit for digital subscriber line communication systems | |
WO1998027713A1 (en) | Passive distributed filter system and method | |
JP4289799B2 (en) | Low-pass filter device with built-in isolator and personal device having the device | |
US20020041676A1 (en) | POTS splitter | |
US6473507B1 (en) | Apparatus and method for isolating transients associated with a digital subscriber line | |
US6483914B1 (en) | Telephone filter arrangement | |
CA2692156A1 (en) | Apparatus, method and system for providing new communication services over existing wiring | |
WO2001006737A1 (en) | Odd-order low-pass pots device filter | |
US6845157B1 (en) | Linear polarity guard and method for DSL-ready pots devices | |
US20020141570A1 (en) | Low-pass filter usable with caller ID device | |
EP1318653B1 (en) | Line interface for combining a voice band signal and an XDSL signal on a twisted-pair copper line |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: PARADYNE CORPORATION, FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:BINGEL, THOMAS;HAZEN, RAMON;REEL/FRAME:010849/0823 Effective date: 20000522 |
|
AS | Assignment |
Owner name: FOOTHILL CAPITAL CORPORATION, CALIFORNIA Free format text: SECURITY AGREEMENT;ASSIGNOR:PARADYNE CORPORATION;REEL/FRAME:012211/0350 Effective date: 20010716 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
REMI | Maintenance fee reminder mailed | ||
FPAY | Fee payment |
Year of fee payment: 4 |
|
SULP | Surcharge for late payment | ||
AS | Assignment |
Owner name: PARADYNE CORPORATION, FLORIDA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:WELLS FARGO FOOTHILL, INC., F/K/A FOOTHILL CAPITAL CORPORATION;REEL/FRAME:021679/0074 Effective date: 20041216 |
|
AS | Assignment |
Owner name: PARADYNE NETWORKS, INC., FLORIDA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PARADYNE CORPORATION;REEL/FRAME:021773/0243 Effective date: 20081022 |
|
FEPP | Fee payment procedure |
Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
AS | Assignment |
Owner name: RAWOR SYSTEMS DEVELOPMENT LLC, DELAWARE Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PARADYNE CORPORATION;REEL/FRAME:022151/0213 Effective date: 20080905 |
|
FEPP | Fee payment procedure |
Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
AS | Assignment |
Owner name: CALLAHAN CELLULAR L.L.C., DELAWARE Free format text: MERGER;ASSIGNOR:RAWOR SYSTEMS DEVELOPMENT LLC;REEL/FRAME:037470/0450 Effective date: 20150826 |
|
FPAY | Fee payment |
Year of fee payment: 12 |